Exercise-induced proteinuria? Urinalysis reveals an excessive level of protein, but your patient is a runner. How concerned should you be? CASE c As part of a routine physical examination, urinalysis reveals that a patient new to your practice is excreting an excessive level of protein. The patient is physically fit and shared during the history taking that he is an avid runner. The physical examination and other laboratory values were unremarkable. How concerned should you be about the finding of proteinuria? E xercise-induced proteinuria is generally benign and a function of the intensity-rather than the duration-of exercise. 1 It occurs most often among athletes participating in such sports as running, swimming, rowing, football, or boxing. 2 It's also transient-lasting 24 to 48 hours. 1 Recognizing exercise-induced proteinuria is fairly straightforward-once you know what to look for. But first, a word about the processes at work.